NEXPERIA 74HCT123D Dual Retriggerable Monostable Multivibrator IC, SOIC-16

The NEXPERIA 74HCT123D is a sophisticated dual retriggerable monostable multivibrator integrated circuit with a dedicated reset function. This device is specifically designed for generating precise output pulses, with the width controlled by the selection of an external resistor (REXT) and capacitor (CEXT). It is fully pin-compatible with low-power Schottky TTL (LSTTL) logic families, ensuring easy integration into a wide range of existing designs.

A key feature is its high noise immunity. The Schmitt-trigger action on the nA and nB inputs makes the circuit highly tolerant to slower input rise and fall times, which is essential for reliable operation in electrically noisy environments typical of industrial and consumer electronics applications.

Output Pulse Control

The IC provides three distinct methods for controlling the output pulse. First, the basic pulse width is programmed via external timing components. Second, the basic output pulse can be extended indefinitely through retriggering on the gated active-low (nA) or active-high (nB) edge inputs, allowing for pulse periods as long as required, even up to a 100% duty factor. Third, any output delay can be terminated immediately by applying a low-going edge to the direct reset input (nRD), which also inhibits further triggering during the reset.

Applications

Its versatility makes it ideal for applications requiring precision timing, pulse shaping, and delay generation. Common uses include debouncing switches, creating timing delays in sequential logic, and generating long-duration pulses for control systems in both industrial equipment and consumer electronic products. The combination of retriggerability and a direct reset offers designers exceptional flexibility in circuit timing.

With its robust specification, including a wide operating temperature range and a compact SOIC-16 package, the 74HCT123D is a reliable and high-performance IC